diff --git a/src/mat.cpp b/src/mat.cpp
index 1e92f8039..eaeb8c5b1 100644
--- a/src/mat.cpp
+++ b/src/mat.cpp
@@ -33,32 +33,6 @@
 
 namespace ncnn {
 
-Mat& Mat::operator=(const Mat& m)
-{
-    if (this == &m)
-        return *this;
-
-    if (m.refcount)
-        NCNN_XADD(m.refcount, 1);
-
-    release();
-
-    data = m.data;
-    refcount = m.refcount;
-    elemsize = m.elemsize;
-    elempack = m.elempack;
-    allocator = m.allocator;
-
-    dims = m.dims;
-    w = m.w;
-    h = m.h;
-    c = m.c;
-
-    cstep = m.cstep;
-
-    return *this;
-}
-
 Mat Mat::clone(Allocator* _allocator) const
 {
     if (empty())
@@ -408,64 +382,7 @@ void Mat::create_like(const VkImageMat& im, Allocator* _allocator)
 }
 #endif // NCNN_VULKAN
 
-void Mat::addref()
-{
-    if (refcount)
-        NCNN_XADD(refcount, 1);
-}
-
-void Mat::release()
-{
-    if (refcount && NCNN_XADD(refcount, -1) == 1)
-    {
-        if (allocator)
-            allocator->fastFree(data);
-        else
-            fastFree(data);
-    }
-
-    data = 0;
-
-    elemsize = 0;
-    elempack = 0;
-
-    dims = 0;
-    w = 0;
-    h = 0;
-    c = 0;
-
-    cstep = 0;
-
-    refcount = 0;
-}
-
 #if NCNN_VULKAN
-VkMat& VkMat::operator=(const VkMat& m)
-{
-    if (this == &m)
-        return *this;
-
-    if (m.refcount)
-        NCNN_XADD(m.refcount, 1);
-
-    release();
-
-    data = m.data;
-    refcount = m.refcount;
-    elemsize = m.elemsize;
-    elempack = m.elempack;
-    allocator = m.allocator;
-
-    dims = m.dims;
-    w = m.w;
-    h = m.h;
-    c = m.c;
-
-    cstep = m.cstep;
-
-    return *this;
-}
-
 void VkMat::create(int _w, size_t _elemsize, VkAllocator* _allocator)
 {
     if (dims == 1 && w == _w && elemsize == _elemsize && elempack == 1 && allocator == _allocator)
@@ -673,61 +590,6 @@ void VkMat::create_like(const VkImageMat& im, VkAllocator* _allocator)
         create(im.w, im.h, im.c, im.elemsize, im.elempack, _allocator);
 }
 
-void VkMat::addref()
-{
-    if (refcount)
-        NCNN_XADD(refcount, 1);
-}
-
-void VkMat::release()
-{
-    if (refcount && NCNN_XADD(refcount, -1) == 1)
-    {
-        if (allocator && data)
-        {
-            allocator->fastFree(data);
-        }
-    }
-
-    data = 0;
-
-    elemsize = 0;
-    elempack = 0;
-
-    dims = 0;
-    w = 0;
-    h = 0;
-    c = 0;
-
-    cstep = 0;
-
-    refcount = 0;
-}
-
-VkImageMat& VkImageMat::operator=(const VkImageMat& m)
-{
-    if (this == &m)
-        return *this;
-
-    if (m.refcount)
-        NCNN_XADD(m.refcount, 1);
-
-    release();
-
-    data = m.data;
-    refcount = m.refcount;
-    elemsize = m.elemsize;
-    elempack = m.elempack;
-    allocator = m.allocator;
-
-    dims = m.dims;
-    w = m.w;
-    h = m.h;
-    c = m.c;
-
-    return *this;
-}
-
 void VkImageMat::create(int _w, size_t _elemsize, VkAllocator* _allocator)
 {
     if (dims == 1 && w == _w && elemsize == _elemsize && elempack == 1 && allocator == _allocator)
@@ -922,35 +784,6 @@ void VkImageMat::create_like(const VkImageMat& im, VkAllocator* _allocator)
     if (_dims == 3)
         create(im.w, im.h, im.c, im.elemsize, im.elempack, _allocator);
 }
-
-void VkImageMat::addref()
-{
-    if (refcount)
-        NCNN_XADD(refcount, 1);
-}
-
-void VkImageMat::release()
-{
-    if (refcount && NCNN_XADD(refcount, -1) == 1)
-    {
-        if (allocator && data)
-        {
-            allocator->fastFree(data);
-        }
-    }
-
-    data = 0;
-
-    elemsize = 0;
-    elempack = 0;
-
-    dims = 0;
-    w = 0;
-    h = 0;
-    c = 0;
-
-    refcount = 0;
-}
 #endif // NCNN_VULKAN
 
 void Mat::substract_mean_normalize(const float* mean_vals, const float* norm_vals)
diff --git a/src/mat.h b/src/mat.h
index 11fb9682e..e623cabf7 100644
--- a/src/mat.h
+++ b/src/mat.h
@@ -960,6 +960,63 @@ inline void Mat::fill(T _v)
     }
 }
 
+inline Mat& Mat::operator=(const Mat& m)
+{
+    if (this == &m)
+        return *this;
+
+    if (m.refcount)
+        NCNN_XADD(m.refcount, 1);
+
+    release();
+
+    data = m.data;
+    refcount = m.refcount;
+    elemsize = m.elemsize;
+    elempack = m.elempack;
+    allocator = m.allocator;
+
+    dims = m.dims;
+    w = m.w;
+    h = m.h;
+    c = m.c;
+
+    cstep = m.cstep;
+
+    return *this;
+}
+
+inline void Mat::addref()
+{
+    if (refcount)
+        NCNN_XADD(refcount, 1);
+}
+
+inline void Mat::release()
+{
+    if (refcount && NCNN_XADD(refcount, -1) == 1)
+    {
+        if (allocator)
+            allocator->fastFree(data);
+        else
+            fastFree(data);
+    }
+
+    data = 0;
+
+    elemsize = 0;
+    elempack = 0;
+
+    dims = 0;
+    w = 0;
+    h = 0;
+    c = 0;
+
+    cstep = 0;
+
+    refcount = 0;
+}
+
 inline bool Mat::empty() const
 {
     return data == 0 || total() == 0;
@@ -1163,6 +1220,32 @@ inline VkMat::~VkMat()
     release();
 }
 
+inline VkMat& VkMat::operator=(const VkMat& m)
+{
+    if (this == &m)
+        return *this;
+
+    if (m.refcount)
+        NCNN_XADD(m.refcount, 1);
+
+    release();
+
+    data = m.data;
+    refcount = m.refcount;
+    elemsize = m.elemsize;
+    elempack = m.elempack;
+    allocator = m.allocator;
+
+    dims = m.dims;
+    w = m.w;
+    h = m.h;
+    c = m.c;
+
+    cstep = m.cstep;
+
+    return *this;
+}
+
 inline Mat VkMat::mapped() const
 {
     if (!allocator->mappable)
@@ -1188,6 +1271,37 @@ inline void* VkMat::mapped_ptr() const
     return (unsigned char*)data->mapped_ptr + data->offset;
 }
 
+inline void VkMat::addref()
+{
+    if (refcount)
+        NCNN_XADD(refcount, 1);
+}
+
+inline void VkMat::release()
+{
+    if (refcount && NCNN_XADD(refcount, -1) == 1)
+    {
+        if (allocator && data)
+        {
+            allocator->fastFree(data);
+        }
+    }
+
+    data = 0;
+
+    elemsize = 0;
+    elempack = 0;
+
+    dims = 0;
+    w = 0;
+    h = 0;
+    c = 0;
+
+    cstep = 0;
+
+    refcount = 0;
+}
+
 inline bool VkMat::empty() const
 {
     return data == 0 || total() == 0;
@@ -1312,6 +1426,30 @@ inline VkImageMat::~VkImageMat()
     release();
 }
 
+inline VkImageMat& VkImageMat::operator=(const VkImageMat& m)
+{
+    if (this == &m)
+        return *this;
+
+    if (m.refcount)
+        NCNN_XADD(m.refcount, 1);
+
+    release();
+
+    data = m.data;
+    refcount = m.refcount;
+    elemsize = m.elemsize;
+    elempack = m.elempack;
+    allocator = m.allocator;
+
+    dims = m.dims;
+    w = m.w;
+    h = m.h;
+    c = m.c;
+
+    return *this;
+}
+
 inline Mat VkImageMat::mapped() const
 {
     if (!allocator->mappable || !data->mapped_ptr)
@@ -1337,6 +1475,35 @@ inline void* VkImageMat::mapped_ptr() const
     return (unsigned char*)data->mapped_ptr + data->bind_offset;
 }
 
+inline void VkImageMat::addref()
+{
+    if (refcount)
+        NCNN_XADD(refcount, 1);
+}
+
+inline void VkImageMat::release()
+{
+    if (refcount && NCNN_XADD(refcount, -1) == 1)
+    {
+        if (allocator && data)
+        {
+            allocator->fastFree(data);
+        }
+    }
+
+    data = 0;
+
+    elemsize = 0;
+    elempack = 0;
+
+    dims = 0;
+    w = 0;
+    h = 0;
+    c = 0;
+
+    refcount = 0;
+}
+
 inline bool VkImageMat::empty() const
 {
     return data == 0 || total() == 0;